<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    /* div {
        width: 100px;
        height: 100px;
        background: lightblue;
        margin: 100px;
    } */
</style>


<body>
    <!-- <div></div>
    <div></div> -->
    <!-- <div style="border: 1px solid #000;overflow: hidden">
        <div style="width: 100px;height: 100px;background: #eee;float: left;"></div>
    </div> -->
    <div style="width:250px;height:200px;background: gray">
        <div style="height: 100px;width: 100px;float: left;background: lightblue">我是一个左浮动的元素</div>
        <div style="width: 200px; height: 200px;background: #eee">我是一个没有设置浮动,
            也没有触发 BFC 元素, width: 200px; height:200px; background: #eee;</div>
    </div>

</body>

</html>